New Delhi: The genetics of nearby mice can have a large impact on one animal's weight and health, a new research has found.Most traits are...

New Delhi: The genetics of nearby mice can have a large impact on one animal's weight and health, a new research has found.Most traits are genetically controlled to some extent, for example one's sleep preferences have a genetic component.But nothing happens in isolation, so if your partner is a night owl and keeps you awake later than you'd like, their genotypes might be partly to blame.The research by Amelie Baud and Oliver Stegle of the European Bioinformatics Institute (EMBL - EBI) in Hinxton, United Kingdom, has been published in PLOS Genetics.

"People influence your behaviour, health and well-being, and you influence theirs - this much we know already,” says Amelie Baud of EMBL-EBI, who led the study.“What's been missing is recognition that there is a genetic basis for this," she explains.

"If you're a researcher looking for links between genotypes and disease, it is very important to look not only at your patient but also at their social environment." Research into 'social genetic effects' can help patients and doctors identify the best way to intervene when a patient's health is affected by their partner."People choose each other, and know they influence one another," Baud continues.

"But often they are not aware of how this works." Research on social genetic effects can uncover the biological mechanisms that determine how individuals influence one another.The influence of a social partner can be mediated by so many traits that it would be unrealistic to measure them all.By contrast, measuring the genotypes of a patient's partner is straightforward and can reveal important drivers.

"Imagine you are a morning person and your partner is a night owl (and) every night you end up going to sleep later than you'd like," explains Baud."Now, say you develop an illness, but don't mention the sleep situation to your doctor because you don't know that it's important (and even) your doctor doesn't ask you because she doesn't know it's relevant.” But if research showed there was indeed a connection between your illness and the genes that control your partner's sleeping pattern then your doctor could better probe your life habits and give useful advice, the scientist adds.

“You and your night owl could then make the right change to ensure you get the sleep you need to heal (and) with this change, you would be mitigating the negative influence of the night owl's genotypes on your health.

" The researchers used two strains of mice, grey and black, and set them up as unrelated 'roommates' in different combinations.They studied social genetic effects by measuring associations between traits such as wound healing, body weight, anxiety and depressed mood in individual mice and the genetic makeup (strain) of their cage mates."We only measured traits like healing, anxiety and body weight in mice and genotypes in their cage mates (and) we found a surprisingly high contribution of the strain of the cage mates to variation in these measures.

" The researchers also re-analysed an existing dataset from 2,500 genetically unique mice to investigate more health-related traits, studying a population that is genetically more similar to the human population.They found that social genetic effects explained up to 29 per cent of phenotypic variance in the traits measured.The traits most affected were wound healing, anxiety, immune function, and body weight.